Blood pressure tourniquet



May 10, 1932. PLESCH 1,857,567

BLOOD PRES SURE TOURNIQUET 7 1 Filed May 27, 1931 2 Sheets-Shet 1 May10, 1932.

J. PLESCH BLOOQ PRESSURE TOURNIQUET 2 Sheets-Shet 2 Filed May 27, 1931Patented May 10, 1932 UNITED STATES P JOHANN PLESCH, OEBERLIN, sear/mm,1

BLoonPREssURn monnivroun'r Application filed May 27, 1931, Serial No,5&Q42'3, and in Germany June 8, 1939. I

the strap. In the otherkind the strap forms an air cushion throughoutits length, and makes more than a complete turn round the arm, accordingto the thickness of the latter. There may be two or more complete turnsin the case of a child. This leads to inaccurate hydrodynamic resultswhen making the measurement. Put shortly, the air cushion is too smallin one case and too large in the other.

The object of my invention is to remove this defect, and to this end Iuse a strap which is inflatable throughout its length but only becomeseffective, as an air cushion, tothe extent of whatever portion thereofis required to make one turn round the arm. For this purpose the straphas attached to one end thereof a fastener through which the other endis drawn to tighten the strap, and the fastener, when put intooperation, applies a grip across the strap, so that the loose portionofthe air cushion, drawn through the fastener, is shut off from theremaining part.

Another advantage of the improved tourniquet is that the fastener canoperate at any desired angle across the part which it grips, so that thestrap can accommodate itself closely to the arm, more so than is thecase with the usual fasteners.

After inflation the whole circumference of the arm is effective forenabling pulsation to be observed.

To ensure that the air pressure compresses only the arm, without bulgingthe outside wall of the cushion and giving a wrong impression in regardtothe pulse action, the outside wall is reinforced by a non-extensiblelining, e. g. wire fabric, thin sheet metal or the like, which does notinterfere with the transverse shutting off of part of the air cushion,but even' assists it. The inflated strap consequently onlybulges'inwards, instead of assuming a bi-convex shape, as was hithertothe case.

A blood pressure tourniquet according to the inventionis shownin theaccompanying 1; T OFFICE] f1 drawings, 'F ljibeinga cross-sectiontheneof, 2 and 5 being elevations, and Figs.

'3 and 4 being cross-sections showing the fastener in two positions.

L .The-eover-a'i-s placed ron-n-da strip biof metal,-so that ean-notbestretched longi taudinally, and'also cannot be stretched transverselyif; the strip 6 is of woven wire or sheet metal. There is aniinsidelayer cvoff rubber, leaving a cavity 4 communicating with a tube 6, forinflation by means of air or other gas, or for-introducing a liquid, e..g.

glyee-rine. v I a I strap has at one end a loop fiyvhereby itis engagedwith part ,g'ofthe'fastening device. The fastening device consists m'part.

of {a tribe 1 with portions of itswall' cut away to afford a passageforthe fnee end of the .strap'b Thegpartjg aportion offlhe tube wall;between the twogaps. At t the. ends of the tube there are caps 9n, n,and within the tube is a rod 2' of circular cross-section, having at itsends excentric pivots whereby it is mounted in .thesaid caps. The freeend of the strap passes through the tube between the tube Wall and theexcentrically mounted rod '5, and by turning the rod the strap canbesqueezed against the'tube wall and thusfastened. The rod 'is'rotated bymeans of a handle at one of itsends, and it has upon it a rotatablesheath 1" enabling the strap to slide over it easily when not squeezed.There is a thick bead s at the free end of the strap, preventing itscomplete withdrawal from the tube h.

Fig. 4 shows the rod 5 ma position allowit ing the free end of the straptoslide freely thereon, when adjusting it on the patients arm. Afteradjustment the strap is tightened as required, and the handle is is thenrotated to the'position shown in Fig. 3, causing the rod d to squeezethe free end of the strap, and

hold it fast. If thepatients arm is approximately cylindrical at thepart to which the strap is applied the strap assumes a correspondingshape, as shown in Fig.2. If the arm is tapered the strap assumes theconical shape shown in-Fig. 5. i

When the strap is worn out, or is to be an i c in said tube forexcentric rotatiomthe part changed for one of a different size, thefastener need not be discarded. The cap a can be'removed, afterunscrewing a screw u by means of which it is held, and the loop f canthen be slipped off the part 9, a fresh strap being substituted,whereupon the cap n is replaced. o

What is claimed is: y

1. A blood-pressure tourniquet, forming an air cushion throughout itslength, charaoterized in that the strap has at one end a fastener,through which the other end passes and by which said other end can begripped along a transverse portion thereof, so that the air cushion isclosed by the grip, and the 7 portion of the strap drawn through thefastener is not inflated, said portion drawn through the fastener havingan enlargement (s) preventing complete withdrawal thereof from thefastener. i

2. A blood pressure tourniquet according to claim 1, characterized inthat its outer layer is soreinforced by a non-extensible but flexibleinlay b) that when under pressure the strap-can only expand inwards;

3. A'blood pressure tourniquet according to claim 1, characterized inthat the fastener comprises a'tube. cut away so as to leave only twolongitudinal parts (h, g), with two caps (m, n) on said tube, and a rodmounted h) of the tube forming a seat against which the strip isgripped, and the part (9) having the strap attached thereto. g Theforegoing specification signed at-Berlin, Germany, this 15th day of May,1931.

' JOHANN= PLESCH.

